Lost customer for life!

I bought a Whirlpool oven and hob 2 years ago from Tafelberg. Literally 4 days after it falls out of warranty based on invoice date, i go back with a problem and get told...tough. Thing is. I was invoiced on one date and didnt take delivery of the goods for a few more weeks but they are claiming they only work on invoice date. How can i fall in my guarantee date if i haven't even received the product. I have spent a lot of money at Tafelberg over the years...never again! Appalling attitude and service.